Performance Cam Shafts and Stage 2 Engines

[bozzzydmc]

Hi Stuart

Thanks for that.

Can i ask why or how you came to change these out for new 'OEM' parts after buying these new hoses. Any idea why they have made a difference ?

[Chris Williams]

Very strange,
Wonder if this will happen with me as I have all Herveys S/S replacement hoses fitted :roll:
Chris

[bozzzydmc]

I too have SpecialT's SS braided hoses but my fuel pressure are all exactly to spec. Im trying to work out why the other DMUK hoses would cause these 'fluctuations' in fuel pressure? At the end of the day the 'banjos' are the same size on either end of my hoses, I assume they are on the DMUK ones ??

[Chris Williams]

Dan,
Dont suppose you have the Bosch part number for the 260 metering head do you?
Ta.
Chris

[NickT]

A quick tip Chris,

The metering flap on the Volvo engine is 1cm in diameter larger than the De Lorean oem one. You will need this as well as the fuel distributor.
If you don't replace them as a matched unit you will get a completely different fuel curve for your engine requirements.
In Yorkshire engineering terms it will be "as rich as chuff at bottom end".

Cheers.

NickT.

[NickT]

bozzzydmc Wrote:I too have SpecialT's SS braided hoses but my fuel pressure are all exactly to spec. Im trying to work out why the other DMUK hoses would cause these 'fluctuations' in fuel pressure? At the end of the day the 'banjos' are the same size on either end of my hoses, I assume they are on the DMUK ones ??

I wonder if the bore of the hose was different or if the pipe flexed under higher pressure. Ask Emagine to cut one in half and have a look

NickT.

[Daniel Shane]

Hi

Nick T is correct, There Flap is larger on the Volvo.

No need to cut one open, I have a box full of the bloody things there that I can chop up

Dan

[Rich H]

I would suspect the DMUK ones swell under pressure.

When the injector 'cracks' the sudden release will cause the hose to shrink back, and the injector to close.

It will then take a moment for the metering head to 'pump up' the hose again before the injector 'cracks' again....resulting in oscillation.

You shouldn't have this problem with the stainless ones, because they don't swell, or the OEM ones because they have a hard plastic liner.

[Emagine]

It only really ever shows up in engine idle on the stage II engines. When I only had the stage I and the DMUK hoses all was fine.

Gotta love these cars and engines..... look at my fuse thread to see what I mean lol.

[Daniel Shane]

RichH Wrote:I would suspect the DMUK ones swell under pressure.

When the injector 'cracks' the sudden release will cause the hose to shrink back, and the injector to close.

It will then take a moment for the metering head to 'pump up' the hose again before the injector 'cracks' again....resulting in oscillation.

You shouldn't have this problem with the stainless ones, because they don't swell, or the OEM ones because they have a hard plastic liner.

Exactly What happens. In fact if you hold one in your hands when the engine is running you can feel it pulse.

As Stuart said there ok on stock engines.

Never really liked them anyway :wink:

Dan

[Guinney1971]

Quote:Never really liked them anyway :wink: Dan

lol.... actually, I wasnt too much of a fan of the DMUK hoses either after the one to the CPR failed on Flopsy (fitting came away from pipe), and it decided to p**s petrol in the direction of a nice hot mainfold last summer.....

[Emagine]

Well, I liked them. I had the nice chav blue stripe version

Now I'm back to the old school black variety.

As on the other thread about EuroTec, I seem to have decided to do everything last minute to get Maddie ready.

Plus I'm doing this Candy Run thing in July too, so I need her running as good as gold for that!

[stunned_monkey]

Still around and still reading the odd post here and there.

There were TWO types of hoses made for DMUK, and both are 100% safety guaranteed and insured by the manufacturer to this day. The hose Claire is talking about was also fitted to my car and is still working perfectly well after more miles and more time. The same type of hose has been used on countless cars and is rated for 10 bar with unleaded fuel, and a hell of a lot more reliable than the original engine bay nylon hose!!! This is easily identifiable as being a flexible black rubber hose with a green stripe.

However the injector pulse problem (identified by Dave and me on the very first set of hoses as fitted to my own engine on #1458) was rectified by a thermoplastic hose which is expansion free - being rated for some 200bar - the prototype set is still to this day fitted to Claire's car, correct me if I'm wrong. Also fitted to, among others, the Explodaview car and featured on the poster. This is identified as being a stiff, shiny black hose with a blue stripe in some cases. This *still* causes problems on *some* engines, but it is not an issue with the hose. Renault issued a recall on the R30TX for problems of poor running at idle and supplied a fuel dampener (basically an accumulator) to combat oscillation in the control pressure line. Renault used solid steel injector lines!

Unfortunately this recall is no longer available.

Any questions, mail me on martin@delorean.co.uk

[Daniel Shane]

Well I have a few sets of the new type hose here and on pulling the hose from the bango on one of the CPR lines it came apart with very little effort.

I have Spoken to A1 Hydraulics, http://www.a1hydraulics.co.uk/ , who produced them as well as the braided clutch line and brake lines that DMCL supplied and they dont understand both the pulsing problem or why SOME of them come apart. Im not blaming there workmanship as it is excellent just that they not make fuel hoses that often, there a hydraulic company at the end of the day. There Clutch and brake lines are very good

The problem was never really rectified as Stuart's car, Nigel's Right Hander and Arron's car all display slight hesitation on light throttle at about 2000 RPM, you could feel the pulsing. I know as I have driven all of these cars over long distances and not just around the block. The warmer the cars gets the worse the pulsing gets. Now all of these cars had complete hose sets on them, and the problem is more to do with the metering head to injector hoses.

Also the problem with the Delorean was never at idle it was under acceleration and if you replaced the hoses with OEM ones the problems went away, so I do blame the hoses. If it's not the hoses then can someone explain why you can feel them pulse when you hold them and why there is this problem ???

If you want ones that dont pulse however then braided or hard ones are the way to go IMHO.

Dan

P.S. I have spoken to A1 Hydraulics, http://www.a1hydraulics.co.uk/ and they will supply directly to customers. There prices are very good too

[bozzzydmc]

Daniel Shane Wrote:Well I have a few sets of the new type hose here and on pulling the hose from the bango on one of the CPR lines it came apart with very little effort.

I

I find that statement very worrying, I wonder how many cars have a potential problem that needs to be checked before something 'nasty' happens.

Dan please can you confirm what colour the 'banding' is on the hoses you are taking about.